Online Exam System

A complete online examination platform. Admins create exams with question sets, assign technical panels, and register colleges. Students register, take MCQ tests, and get scored automatically. Results can be pulled by exam code or filtered by college.

Originally built in 2016 with .NET Framework 4.5.1. Modernized in 2026 to .NET 9 with Clean Architecture.

Version History

Branch	Stack	Status
v1-legacy	ASP.NET MVC 5, EF6, SQL Server LocalDB, .NET Framework 4.5.1	Preserved (original code)
v2-modern / master	ASP.NET Core 9, EF Core 9, PostgreSQL, Carter, MediatR, JWT	Current

What changed in v2

Area	v1 (2016)	v2 (2026)
Runtime	.NET Framework 4.5.1	.NET 9
Web framework	ASP.NET MVC 5 (Razor views)	ASP.NET Core 9 (REST API + Carter)
ORM	Entity Framework 6	EF Core 9
Database	SQL Server LocalDB (Windows only)	PostgreSQL (cross-platform, Docker)
Auth	Forms auth + cookies	JWT + BCrypt
Passwords	Plaintext	BCrypt hashed
DI	None (manual instantiation)	Built-in Microsoft DI
Validation	None	FluentValidation
CQRS	None	MediatR
Logging	Console.WriteLine	Serilog (structured)
API docs	None	Scalar (OpenAPI)
Architecture	3-tier (tightly coupled)	Clean Architecture (Domain → Application → Infrastructure → API)
Entities	17 (with duplicates)	11 (consolidated)
Tests	None	xUnit + FluentAssertions

What it does

Admin flow:

1. Create locations, companies, colleges
2. Create question sets and add MCQ questions (4 options + answer key)
3. Create technical panels by selecting employees
4. Create examinations — assign question set, panel, college, date, duration, cutoff
5. Assign panel to exam
6. View reports — results ranked by score, students by college

Student flow:

1. Register for an exam with USN, personal details, and exam code
2. Get questions (answer keys are never exposed to the student)
3. Submit answers — auto-graded against answer keys, pass/fail against cutoff
4. Result stored with score, total, and pass status

API Endpoints

Auth

Method	Endpoint	Auth	Description
POST	/api/auth/register	Public	Register user with BCrypt hash, returns JWT
POST	/api/auth/login	Public	Login, returns JWT

Admin — Setup

Method	Endpoint	Auth	Description
GET/POST/PUT/DELETE	/api/locations	JWT	Location CRUD
GET/POST/DELETE	/api/companies	JWT	Company CRUD
GET/POST/DELETE	/api/colleges	JWT	College CRUD
GET/POST/DELETE	/api/employees	JWT	Employee CRUD + filter by location

Admin — Exam Management

Method	Endpoint	Auth	Description
GET/POST/DELETE	/api/question-sets	JWT	Question set CRUD
GET/POST	/api/question-sets/:id/questions	JWT	Questions within a set
GET/PUT/DELETE	/api/questions/:id	JWT	Individual question CRUD
GET/POST/DELETE	/api/technical-panels	JWT	Panel CRUD (M:M with employees)
GET/POST	/api/exams	JWT	Exam CRUD (marks question set as used)
GET	/api/exams/by-code/:code	JWT	Lookup exam by code
POST	/api/exams/:id/assign-panel	JWT	Assign panel to exam

Student — Exam Taking

Method	Endpoint	Auth	Description
POST	/api/exam-taking/register	Public	Register for exam with USN + exam code
GET	/api/exam-taking/:examCode/questions	Public	Get questions (no answer keys)
POST	/api/exam-taking/:examCode/submit/:studentId	Public	Submit answers, auto-grade

Reports

Method	Endpoint	Auth	Description
GET	/api/reports/results/:examCode	JWT	Results ranked by score with pass %
GET	/api/reports/students/:collegeId	JWT	Students by college with avg scores

Tech Stack

• ASP.NET Core 9 — Minimal API with Carter endpoint modules
• EF Core 9 — Code-First with PostgreSQL
• MediatR — CQRS pattern for auth commands
• FluentValidation — Request validation
• Mapster — Object mapping
• BCrypt — Password hashing
• JWT Bearer — Authentication
• Serilog — Structured logging
• Scalar — OpenAPI documentation (at /scalar)
• xUnit + FluentAssertions — Testing
• Docker — PostgreSQL container

Project Structure

src/
├── OnlineExam.Domain/              # Entities, enums, interfaces (zero deps)
├── OnlineExam.Application/         # Commands, handlers, validators (MediatR + FluentValidation)
├── OnlineExam.Infrastructure/      # EF Core, repositories, JWT, DI setup
└── OnlineExam.API/                 # Carter endpoints, Serilog, Scalar, Program.cs

tests/
├── OnlineExam.Domain.Tests/
└── OnlineExam.Application.Tests/

Running it

# Prerequisites: .NET 9 SDK, Docker

# Start PostgreSQL
docker compose up -d

# Run the API
cd src/OnlineExam.API
dotnet run                    # http://localhost:5000

# API docs
open http://localhost:5000/scalar

Entities

Entity	Purpose
User	Auth — username, email, BCrypt hash, role (Admin/HR/TechnicalPanelist/Student)
Location	Geographic locations for colleges and exams
Company	Companies running recruitment exams
College	Colleges registering students
Employee	Staff assigned to technical panels
TechnicalPanel	Exam invigilators (M:M with employees)
QuestionSet	Group of MCQ questions (marked as used when assigned to exam)
Question	MCQ — text, 4 options (A/B/C/D), correct option
Examination	Exam setup — code, date, duration, cutoff, college, panel, question set
Student	Registered exam takers with academic details
ExamResult	Score per student per exam — auto-graded, pass/fail